Welcome to the forum.
To your query, all you have to do is to update your "A" record to your webhost.
Please use the following steps to review your domain's record with Comcast.
1. Log into your Comcast Business online account using your primary admin email address.
2. Select Websites from the Manage Services menu.
3. Select Edit website.
4. In the Control Panel under Manage Services, select Domain Name.
5. Select the "A" record entry and edit the IP address.*
*This will give you the access, but I do recommend contacting your new webhost for instructions on any steps prior to making the changes on the Comcast side.
Thanks for the quick reply.
I'm having trouble locating the "A" record on step 5. There is no record of any kind on the page. What I get at that point is a list of my domains (only one in my case). There is an edit link next to my domain. If I click that, it takes me to a page with a few things I can change, but still no "A" record. What I get is Registrant contact, Name servers, Auth info code, Domain lock and Registration privacy. None of them seem to be related